Polishing apparatus



'A. E. HAMILTON POLISHING APPARATUS Filed Nov. 14, 1956 July 12, 1938 8 Sheets-Sheet l El 9 N wk om mm 0 w? m 0% u .n f. u E E1: n N 01 PM? 1 F E m. wu H om mm Wm NM 1211111. 1:. t mm INVENTOR July 12, 1938.

TA. E. HAMILTON POLISHING APPARATUS Filed Nov. 14/1936 8 Sheets-Sheet 2 POLI SHING APPARATUS ;ZVENT9R 6 414410575214;

July 12, 1938. A; E, HAMILTON "2,123,111

POLI SHING APPARATUS Filed Nov. 14, 1936 a Sheets-Sheet 4 9 T51 0-2 M m w- 3 INVENTOR July 12,1938.

A. HAMILTON POLISHING APPARATUS Filed NOV. 14, 1936 8 Sheets-Sheet 5 July 12, 1938. A. E. HAMILTON POLISHING APPARATUS Filed Nov. 14,1936

8 Sheets-Sheet 6 JulylZ, 1938. A. E. HAMILTON 2,123,171

POLISHING APPARATUS Filed Nov. 14, 1936 '8 Sheets-Sheet 7 I II II I I l "I v-T- I i l I I II I I II l I INVENTO July 12, 1938.

A. E. HAMILTON POLI SHING APPARATUS Filed Nov. 14, 1936 8 sheets-sheet 8 Patented July 12, 1938 2 UNITED STATES PATENT OFFICE 8 Claims.

My invention relates to polishing or abrading machines and is hereinafter described as employed in the polishing of knife blades or the like, although it will be apparent that it may be employed in the polishing and finishing of other articles.

One object of my invention is to provide means for effecting a cross-polishing of the blanks simultaneously with a polishing operation, in directions length-wise of the blanks, and wherein the emciency of the cross-polishing operation will be the same regardless of the length of feed stroke employed in directions length-wise of the blanks.

Another object of my invention is to provide mechanism for moving the blanks in directions longitudinally of the rollsduring advancing and retracting movements thereof between the rolls, with a V vibratile-reciprocatory motion derived from a hypocyclic crank movement.

Another object of my invention is toprovide a simplified automatic stopping mechanism that is readily adjustable to permit the desired number of abrading strokes or the proper number of polishing strokes, whereby the danger of underworking or over-working of the blanks is eliminated. v

A further object of my invention is toprovide a machine of such form that the various working parts can readily andeasily be adjusted; wherein the parts are fully protected against entry of abrasive and other foreign material, and which shall be capable of emcient and continuous operation.

In the accompanying drawings, Figure 1 is a front view of the machine; Fig. 2 is a plan view thereof, partly in section;- Fig. 3. is aside view thereof; Fig. 4 is aview on an enlarged scale taken on the'line IV-IV of Fig. 1; Fig. 5 is an enlarged view taken onthe line V-V of Fig. 3; Fig. 6 is a view taken on the line VIVI of Fig. 4; Fig. 7 is a view taken on the line VIIVI I of Fig. 6; .Fig. 8 is a view, on an enlarged scale,

taken on the line VIII--VIII of Fig. 2; Fig. 9 is a view taken on the line IX-IX of Fig. 8, and Fig. 10 is a sectional plan view of the structure of Fig. 9.

Briefly, the structure embodying my invention comprises a. roll stand on which a pair of opposed rolls is pivotally supported for periodic oscillatory movements about parallel axes, in directions toward and away from each other. A blade or blank holder is supported for reciprocation in a rectilinear path to move the blades carried thereby forwardly between the rolls when they are in spaced-apart position, and to withdraw the blades,

the rolls being moved into engagement with the blades to efifect a polishing operation thereon as they are being withdrawn from between the rolls. Each roll is provided with a driving motor.

Mechanisms are provided for oscillating the 5 rolls and for reciprocating the blade holder in synchronism, and after the blades have been subjected to a predetermined number of polishing strokes, an automatic stoppingdevice is actuated to stop the operation of the machine, there- 10 by assuring proper polishing of the blades. The length of stroke of the blade-reciprocating mechanism is, of course, adjusted to permit polishing of blades of various lengths. Provision is also rn'izde for adjusting the polishing pressure of the ro ls.

Simultaneously with reciprocation of the blade holder toward and away from the rolls, motion is imparted to the holder to move it in directions longitudinally of the rolls with a vibratile-reciprocatory motion derived from a hypocyclic crank movement, whereby the points of engagement between the rolls and the blades: are constantly changing at a variable rateof speed iii-directions longitudinally of-the rolls, and thereby a more uniform polishing action is effected regardless 2f irregularities and unevenness "of the roll suraces.

Referring now more particularly. to Figs. 1, 2, 3 and 8, the machine comprises a base I!) on which is mounted a roll stand comprising a pair of uprights Ii. The uprights carry cross-bars l3 and M which are journalled in the uprights at l5 and I6 respectively, for rocking movement about their respective axes. The rods l3 and I4 respectively carry brackets l1 and I8, which are rigidly secured to their respective rods. The bracket I! is connected to its associated rod or cross-bar I3 by means of a pair of bearing bosses 20 and a boss 2|, which are formed on the bracket l1, and through which bosses the rod l3 extends. Each of the bosses 20 and 2| is provided with a set-screw or a keying device which will hold the bracket ll against movement relative to the rod l3, so that the bracket and the rod can be oscillated in unison about the axis of the rod in a manner to be hereinafter described. The lower bracket I8 is similarly connected to its associated rod I4.

A bracket 22 is connected to the bracket I! at one point by means of a pivot bolt 23, which has threaded connection with the bracket l'l, as shown more clearly in Figs. 2 and 8. The bolt 23 extends through the midpoint of the bracket 22, so that the bracket 22 will have pivotal adjustment on the bolt. The bracket 22 is adjustably connected to the bracket I1 by stud bolts 24, 26 and 26, which have threaded connection with the bracket 22, and whose shanks extend through slots in the bracket H, as shown more clearly in Fig. 1, so that the bracket 22 can be set in various angular positions with respect to the bracket l1.

The bracket 22 has forwardly projecting journals 30 in which are supported the ends of a shaft 3|, which carries a polishing roll 32. The roll may be faced with any desired abrasive or polishing material such as emery, polishing rouge etc., and is here shown as built up of a series of fabric discs which are assembled on the shaft and held thereon by clamping discs 34, which may be held in snugly assembled relation by means of clamping nuts and collars, such as indicated at 65 and 36, that are carried by the shaft 3|. .The fabric discs are, of course, yieldable, and other material such as rubber could be substituted therefor if desired. .For initial grinding and polishing, the discs may have peripheral faces or edges of emery, or be impregnated with emery or the like. The roll shaft 3| is driven from an electric motor 38 that is bolted to the bracket 22.

The bracket H has a yoke-like extension carrying adjusting screws 40 and 4| (Fig. 1), whose ends engage a boss 42, projecting rearwardly from the bracket 22. With the screws 24, 25 and 26 loosened, the screws 40 and 4| can be turned to effect adjustments of :the bracket and the roll 32 carried thereby, relative to the bracket l1, about the pivot bolt 28 as an axis. The brackets can be tightly secured in any such adjusted position by then tightening the bolts 24, 25 and 26. The roll 82 is thereby adjusted relative to a cooperating roll 44 which will be of similar construction to the roll 32.

The roll 44 is mounted upon a shaft 45, that is journalled in extensions 46 of a bracket 41 which is of a form similar to the bracket 22 and is connected to its bracket l8 by a pivot bolt 48. The bracket 41 is adjustable on the bracket I8 by stud bolts 56, 5| and 52 and screws 53 and 54 which respectively correspond in function and operation to the members 24, 25, 26, 40 and 4|. The roll shaft 45 is driven by an electric motor 81 that is mounted on the-bracket 41.

It will be understood that knife blades, or other articles to be ground or polished, will pass between the rolls 32 and- 44, and that in order to effect proper and uniform polishing action, the rolls must be properly spaced apart and be angularly adjustable relative to one another, in order to compensate for unevenness in wear at various points throughout their lengths. It is for this reason that the adjustments above referred to are provided.

The rolls are supported by links or rods for vertical movement relative to one another whereby they can be separated to permit the insertion of blades or other articles to be ground or polished, and then brought into operative relation with said blades to effect a polishing operation thereon while the blades are being drawn from the rolls. The rolls are driven in such direction that they exert a drag on the articles as they are being withdrawn from the pass of the rolls, during the polishing action. In other words, during the polishing operation, the roll surfaces in contact with the blades are moved in a direction opposite to that in which the blades are being moved.

A vertically movable push rod or link 55 is pivotally connected at its upper end to an arm 66 that is rigidly secured to the journal extension 36 of the bracket 22, so that when the rod 66 is raised and lowered, the bracket l'l, together with its associated bracket 22 and roll 32, is oscillated about the axis of the bar ii. The bracket IT has pivotal connection with one end of a link 68, whose other end is pivotally connected to a lever 61 that is pivotally mountedat 62 to the upright H (Figs. 2, 3 and 8). The lower end of the lever 6| is pivotally connected to a link 63 which has pivotal connection also with the bracket l8. It will be seen that by reason of the link connections referred to, the-weight of the bracket l6 and the parts carried thereby, which tends to cause them to move downwardly, will be counterbalanced by the weight of the upper bracket l1 and the parts it supports, and that when the upper roll is moved to a given vertical position,

the lower roll will be correspondingly shifted in the opposite direction. I I

The lower end of the push and pull rod 55 is pivotally connected to a lever 65 whose one end is pivotally connected tothe frame II at 66. A

yoke 61 loosely fits over the forward end of the lever 65 and is yieldably urged toward the base by a spring 68. An adjusting screw 69 is provided in the yoke 61 and bears against the upper edge of the lever 65, so that the spring tension on the lever can be varied. The tension exerted by the spring 68 yieldably urges the rolls toward one another and determines the polishing pressure exerted by the rolls.

The work-supporting and feeding mechanism includes a casing 18 which has a flanged base that is slidably adjustable in slideways formed in the base ID, as shown more clearly in Figs. 1, 3 and 5. Adjustment of the casing 10 on the base It is effected by a screw 1|. This adjustment is provided in order to position the casing 18 relative to the rolls to permit of polishing blades of various lengths.

The casing I6 supports a motor 12, which is provided with a shaft that carries a pinion 16 (Fig. 4). The pinion drives a gear wheel I4, that is mounted on a shaft 15 that is journalled in bearing brackets 16 (Figs. 4 and 5). The shaft 15 carries a worm 11 which meshes with a worm wheel 16. The worm wheel 18 is bolted to a supporting plate 18 that is formed integrally with one end of a shaft 68, the shaft 65 being jour nalled in a bearing sleeve 8| that is carried by the casing 10.

A second plate or disc 16a is secured to the plate 19 in back-to-back relation thereto, and on its inner face is provided with a bearing boss 62 for supporting the shaft 83 of a bevel gear 64. The other end of the shaft 82 is threaded for engagement with a crank member 65 that carries a crank pin 86. The member 85 is slidably adjustable by the screw shaft 83 in guide wings or bosses 81, that are formed on the face of the disc 19a.

Rotative adjustment of the crank pin 86 radially of the worm gear 18 is effected by a bevel pinion 88 that meshes with the gear 84. The pinion 68 is mounted on a shaft 88 that extends centrally through the shaft 88. The shaft 68 is squared at its outer end for the reception of a wrench or handle. It will be seen that the shaft 80, shaft 89, bracket 82 and crank pin member 65 rotate as a unit with the worm wheel 16. The adjustment of the shaft 88 is for the purpose of varying the throw of the crank pin 86, since its radius of movement, and therefore the length of the worm wheel 18.

The crank pin "carries a slide block 99 which is disposed within a slot 8| in a lever 92, the lever" 92 being pivotally mountedcn a shaft 93 that is journalled in bosses projecting upwardly from the bottom of the casing. The upper end of the lever 92, as shown more clearly in Figs. 4 and 6, has pivotal connection with a link 94, that is in turn connected to a rack bar 95. The rack bar 95 is positioned between guide plates 96 which are carried by the casing 19, and is provided with teeth on its opposite faces that are in mesh with segmental gear members 91 and 98, respectively.

The gear members 91 and 98 are mounted on vertical shafts 99 and I99, respectively, that are Journalled in the casing I9. The upper ends of the shafts are connected to cranks MI and I92, respectively, which in turn are respectively connected to links I93 and I94. The links I93 and I94 at their free ends are journalled on a stub shaft I95 (Figs. 8 and 9), which is carried by an anti-friction roll cage I96. The roll cage I96, as shown more clearly in Figs. 8, 9 and 10, consists of a top plate having downwardly extending marginal flanges forming an inverted box which encloses a plate member I89 of a carriage I91. Antifriction rollers I8I that are held in assembled relation within a roller cage I82 are interposed between the top of the plate member I89 and the under side of the upper plate portion of the roll cage I96. A neck portion I83 connects the supporting plate I89 with the frame of the carriage I91 and extends through an elongate slot I84, formed in a sectional bottom plate I85 that is secured to the marginal flanges of the cage I96. Anti-friction rollers I86 and I81 are disposed at opposite sides of the neck I83 in position between the bottom plate I85 and the under side of the plate member I89., The carriage I91 is thus supported in suspension by the roll cage I96 at the ends of the arms I93 and I94.

The carriage I91 is provided with grooved wheels I98 that engage a track bar I99. The bar I99 is, at its ends, mounted upon arms I I9 of a rock shaft III, that is iournalled in the housing 19. It will thus be seen that by oscillating the shaft III, the bar I99 will be moved in directions indicated by the arrows in Fig. 5 and move the carriage I91 relative to the roll cage I96 in directions parallel to the axes of the rolls 32 and 44. This movement of the carriage is effected independently of its movement toward and away from v the rolls, for a purpose to be hereinafter described.

The carriage member I91 has a bracket I I5, which carries a work holder. The ends of the bracket II5 (Figs. 8, 9 and have threaded bosses for the reception of adjusting screws H6. The upper ends of the screws II6 are rotatably connected with a supporting plate I I1. The work holder comprises a pair of hinged plates II8 which are hingedly connected and which are adapted to grasp or clamp blades or other work pieces II9. A pair of threaded eyebolts I29 have swivel connection with the lower plate I I 8 and are movable into slots in the edge of the upper plate, whereupon nuts I2I can be employed to clamp the plates together, then firmly hold the work pieces I I9. The blanks or work pieces I I9 are preferably formed with notches in the edges of their shanks, as shown more clearly in Fig. 10, for engagement with studs I22 on the lower plate I I8, whereby an interlocking effect is had, which prevents pulling the blades out of the holder under the frictional drag of the polishing rolls. Angle clips I23 carried by the lower plate I I8 serve to detachably eeclau l'e the work holder II8 to the supporting plate The arms WI and I92 at their upper ends carry bearing housings I24 and I25 respectively, for the shafts on which the links I93 and I 94 are mounted (Figs. 1, 2, 3 and 8). At their lower ends, the arms MI and I92 are supported on the shafts 99 and I99, above referred to, which are in turn supported in the casing 19. The supporting shafts at the points of pivotal connection of the arms IM and I92 and the links I93 and I 94are effective to prevent horizontal deflection or sagging of the arms and the work holder.

Oscillation of the rock shaft III and the guide track I99 to reciprocate the work holder and the knife blades longitudinally of the rolls, while in the roll pass, is effected by a crank or lever arm I26 (Fig. '5) which is rigidly secured to the rock shaft III. A link or connecting rod I21 is pivotallyconnected to the outer end of the lever arm I26, and atits lower end is connected to-a crank or an extension I28 of a crank shaft I29 (Figs. 5 and 6). The shaft I29 is iournalled in a rotating barrel or cage I39 which in turn is formed on the end of a shaft I3I, that is journalled on a supporting plate I32 which is detachably bolted to the end of the casing 19.

The plate I32 has a cylindrical projection I33 within which is formed a bearing surface for supporting the barrel I39. An internal gear I34 is mounted within the extension I33 and meshes with a gear wheel I35 that is secured to the shaft I29. The shaft I 29 is journalled eccentrically of the shaft I3 I, so that when the shaft I3I is driven, as hereinafter explained, the gear wheel I34 will cause rotation of the gear wheel I 35, during rotation of the shaft I3I, whereby the crank I29 will be rotated on its own axis during movement thereof in a path concentric to the axis of thebarrel I39 and the shaft I3I, thereby producing a hypocycloidalmotion which, through the connecting rod I21 and the rock shaft I II, will be transmitted to the track I99, and produce avibratory and reciprocating movement of said track I 99 and the work holder, in directions longitudinally of the polishing rolls.

This combination of short vibratory movements with the longer reciprocating movements, in.di-

rections longitudinally of the rolls, results in a better and more uniform polishing of knife blades and the like, than would be possible with simple reciprocatory movements, thereby avoiding a tendency toward zones of very high polish and contrasting zones which are less brightly polished, or in other words, eliminating streakiness of polishing which is frequently present when the blades are simply reciprocate'd longitudinally of therolls while being moved into and out of the roll pass.

The shaft I3I carries a bevel gear I31 which is driven from a bevel pinion- I38 that is secured to a shaft I39. The shaft I39 is journalled in bearing bosses upon the supporting plate I32. A pin- 4 throw'of the crank 85, as heretofore referred to, which moves the work into and out of theproll pass,can be made to suit various lengths of knife blades or the like, in order to effect proper polishing thereof, but such adjustment will not affect the vibratory and reciprocatory movements above referred to. In other words, shortening of the feed stroke into and from the'roll pass will not reduce the amplitude of vibratory movements in directions longitudinally of the rolls, so that the efficacy of the cross-polishing action remains the same regardless of the length of feed stroke employed.

The actuation of the lever 65 to effect movement of the polishing rolls 32 and 44 toward and from one another, is effected by the worm wheel 18 which carries a roller I48 (Figs. 1 to 6), which, during rotation of the wheel, periodically engages a camming extension I49 of a crank I50, which is secured to a shaft I5I, that is journalled in the casing 10. At its outer end, the shaft I 5| carries a lever arm I52 which in turn carries a push pin I53 that engages a groove in the under side of the lever 65. It will be seen that as the rock shaft I5I is oscillated during rotation of the worm wheel 18, the lever 65 will be periodically raised to effect separation of the polishing rolls.

This separating movement of the rolls occurs just when the blanks are being advanced into the roll pass, or between the rolls, through forward movement of the carriage I01, as heretofore described. When the carriage is fully advanced, the lever 65 will be permitted to descend and bring the polishing rolls into engagement with the knife blades or otherwork pieces at points adjacent to where they are clamped by the work holder. Thereupon, with the rolls rotating, the carriage is retracted in a direction to draw the work from the roll pass, and the vibratory movements in directions longitudinally of the rolls, as heretofore described, are simultaneously effected.

A guard or shield I55 is provided for preventing the operator getting his hands caught between the rolls (Figs. 3 and 8). The shield is mounted upon a rock shaft I56 that is journalled in the bearing bosses 30. A crank arm I51 is secured to the rock shaft and has connection with a link I58 whose lower end is connected to a lever I59 that is pivotally mounted at I60 to the side of the casing 10. The lever I59 carries a cam roller I6I that has cooperative engagement with a cam disc I62 which is .mounted on the shaft 80. The shield I55 w'ill" therefore. be periodically raised and lowered-during-the operation of the mechanism. The timing or adjustment issuch that the shield will be in its lower or protective position when thecarriage I01 is retracted, and will be raised automatically while the carriage is being advanced toward the roll pass.

A complete polishing or abrading operation ordinarily consists of repeatedly moving the work holder toward and away from the roll pass while oscillating the holder, as above described. For example, the work holder may be advanced and retracted five times. The number of times which the work holder is reciprocated toward and from the pass of the rolls, is variably and automatically controlled by mechanism which includes a rack bar I65 which is slidably supported in a bracket I66 which is secured to the casing 10. The rack bar carries a push rod I61 which is engageable with a rocking lever I10 when the rack bar is advanced to a predetermined point. The lever I10 is pivotally mounted on the side of the casing 10 and engages the pushbutton of a switch IN to break the circuit of the driving motor 12.

The rack bar is actuated by a pinion I13 which is journalled in the bracket I66. Step-by-step movement is imparted to the pinion I13 to advance the rack bar, by the cam I82 which carries a pin I14 which, during each rotation of the cam, will engage one of the teeth of the pinion I13 and impart slight rotative movement thereto. The cam I62 will make one complete rotation for each cycle of reciprocation of the work holder toward and from the roll pass. At certain adjustments of the rack bar and push rod, the cam I62 may rotate perhaps five times before the rack bar is advanced far enough to actuate the lever I10 that breaks the motor circuit.

After the motor circuit has been broken, as above described, the rack bar and its rod I61 will be manually pushed back-away from the lever I 10. Scale markings can be placed on the rod I61, so that it can readily be pushed back such distance that a desired number of rotative movements will be imparted to the pinion I13 before the motor circuit is broken. The retractive movement and adjustment of the rack bar, of course, turn the pinion I13 backwardly, the pinion being at that time out of engagement with the pin I14, and hence free to rotate.

The automatic stop mechanism eliminates too many strokes on abrasive operation, thereby protecting against wearing the material too thin, and, also, assures that for finishing operations the'work will be given a sufficient number of strokes to obtain uniformity of polishing.

A cycle 01' operations is initiated when the vertical push rod 551s in its upper position and the polishing rolls 32 and 44 therefore separated, with blanks II9 secured in the work holder, the driving motors for the rolls 32 and 44 being normally constantly driven. The motor 12 is started, whereupon the work holder will be advanced to move the blanks between the rolls, this movement being effected by the crank 85 which, through the lever 92, rack bar 95, cranks IOI and I02, and links I03 and I04, moves the work holder toward and from the roll pass. When the blanks have been entered between the rolls, the cam roller I48 will pass oiT the extension I49 of the crank shaft I5I, thus releasing the rod and allowing the lifting lever 65 to descend, and the rolls 32 and 44 to move against the blanks. The crank 85 will then have reached the point at which it effects movement of the work holder away from the rolls, during which movement the blanks are polished.

During this retractive movement of the work holder, it is reciprocated in directions longitudinally of the rolls, by the barrel I30 which functions as a crank and acts through the crank I28, the link I21, the crank arm I26, rock shaft III, bar I09, and guide wheels I08, to reciprocate the holder. The work holder carriage is simultaneously oscillated or vibrated during its movement longitudinally of the rolls, within the path of such movement. This oscillation is effected by the hypocycloidal motion produced by the crank shaft I28 whose pinion I engages the stationary ring gear I34, so that there is a turning of the crank I28 upon the crank member I30, both acting upon the link I21.

These operations are automatically repeated until the motor 12 is stopped; Stopping of the motor is effected automatically by the rack bar I65 engaging the switch-operating lever I10. The rack bar is moved outwardly toward the switch lever a predetermined distance during each cycle of movement by the work holder toward and from the roll pass.

I claim as my invention:

1. Polishing apparatus comprising a polishing roll, a work holder, driving mechanism for recurrently moving said work holder toward and from. the polishing roll to move a work piece on the face of the roll, a control device movable into position to interrupt the operation of said driving mechanism, means operable during movement of the driving mechanism for intermittently advancing said control devicetoward the said interrupting position, and means for adjusting the distance of movement required for said control device to become operative.

2. Polishing apparatus comprising a polishing roll, a work holder, driving. mechanism for recurrently moving said work holder toward and from the polishing roll to move a work piece on the face of the roll, a control device movable into position to interrupt the operation of said driv ing mechanism, means operable during each cycle of movement of the work holder for advancing the control device one step toward the said interrupting position, and means for adjusting the distance oi? movement required for said control device to become operative.

3. Polishing apparatus comprising a supporting means, a pair of brackets each pivotally mounted on said supporting means, a polishing roll journalled in each of said brackets, the rolls being mounted in vertically spaced cooperative relation, counter-balancing link connections between said brackets so arranged that the gravitational force imposed upon each bracket is transmitted as a lifting force to the other bracket, a work holder, mechanism for moving the work holder toward and from the rolls, and means operated in timed relation to the movement 01' the work holder for raising and lowering one of said brackets.

4. Polishing apparatus comprising a supporting means, a pair" of brackets each pivotally mounted on said supporting means, a polishing roll journalled in each of said brackets, link connections between said brackets so arrangedthat pivotal movement of one of the brackets will effect movement of the other bracket in the opposite direction, a work holder, mechanism for moving said work holder toward and from the rolls, and means operated in timed relation to said mechanism for oscillating one of said brackets on its pivot.

5. Polishing apparatus comprising a pair of rolls arranged in cooperative relation and with their axes normally in approximate parallelism, a bracket having bearings for one of said rolls, a support for the bracketmeans for tiltably adjusting said bracket on its support, to vary the relative angularity of the rolls, means for moving the rolls toward and away from one another, a work holder, and means for moving the work holder toward and from the roll pass in timed relation to said movement of the rolls.

6. Polishing apparatus comprising a polishing roll, a work holder, means for moving the work holder toward the roll, in a plane generally tangential thereto, means operating in predetermined relation to said movement of the work holder, for moving the roll in directions perpendicular to said plane, to move it out of the path of. work carried by the holder and to then move the roll against the work, means for withdrawing the work holder from the roll, and means for simultaneously imparting combined reciprocatory and shorter vibratory movements to the holder in directions longitudinally of the roll.

7. Polishing apparatus comprising a polishing roll, a work holder, means for moving the work holder toward and from the polishing roll to move a work piece on the face of the roll, and a device operable simultaneously with said means, for effecting combined reciprocatory and shorter vibratory movements of the work holder in directions transversely of the path of movement of the work holder.

8. Polishing apparatus comprising a, pair of cooperatively-mounted polishing rolls, a pivotallymounted bracket for each of said rolls, movable toward and from one another, counter-balancing link connections between said brackets, so arranged that movement of either bracket in one direction will cause movement 01' the other bracket in the opposite direction, a work holder movable to carry a work piece into and from the roll pass, and means operating in synchronism with movement of the work holder toward the roll pass to effect separating movement of the said brackets.

ALFRED E. HAMILTON. 

